A conventional radar sensor unit (radar system) comprises a transceiver circuit having a transmitter including a waveform generator and an analog front end (AFE) including an amplifier and a receiver that includes an AFE (amplifier, mixer, and filter) and an analog-to-digital converter (ADC). The radar system also includes a signal processing module/unit, such as a digital signal processor (DSP) or a microcontroller unit (MCU). A radar chip may provide all these components, except perhaps the signal processing module/unit and antenna(s).
Data processing in a frequency-modulated continuous-wave (FMCW) radar system is performed on a system cycle/frame basis. A FMCW frame includes N (number) of FMCW ramps/chirps. A chirp is a smallest logical unit of data used for FMCW radar processing.
One application for such radar systems is for automotive collision avoidance. In these radar systems, during field operation, the AFE circuits need to be continually monitored to detect failures and/or to improve their performance. In particular, preventing a malfunction in the radar system can be important, and the ability to monitor a failure during radar operation is a desirable feature. In order to satisfy such requirements, a built-in self-test (BIST) circuit or system may be included to test the transceiver circuit during radar system operation.